it supplies 90% of the north korea's energy and substantial amounts of food to keep the north korean population there instead in china. but china has not been willing to do that because it fears that the regime would collapse and the peninsula would reunify. that's what we need to convince china long term it is in their interests. if north korea's nuclear weapons program goes on other countries in the region, japan, south korea, taiwan and others are themselves going to look whether they want nuclear weapons which would obviously make the entire region much more unstable. jon: and for those who wondered whether kim jong-un had staying power as leader of north korea, he just bought himself a whole lot of time in that job, didn't he? >> well i think he showed that the capability of the north koreans has been underestimated and i think you're right. this will be a political boost for him but let's be clear. this rocket-testing program and the work with iran have been going on for decades and they have had some notable failures but each failure tells them something and each success tells